The need for independent monitoring inside detention centres, which has been the subject of fierce criticism in the NT, was a focus of the talks.

"We have a strong commitment in New Zealand to strong and thorough monitoring," Judge Becroft said.

"My role as Children's Commissioner is to conduct that monitoring exercise."

Judge Becroft said his country and the NT had a lot in common, with Maori young people making up 64 per cent of those before youth courts and about 80 per cent in youth detention.

"The challenge [is] dealing with disordered young people, who are disproportionately Indigenous, who are disengaged from school, who are cannabis and alcohol dependent, who've just about always had a history of abuse and neglect themselves," he said.

Judge Becroft said New Zealand was not immune from violent incidents inside youth detention, but he said the system was reserved for the most serious offenders.

"Young offenders need to be held to account — the real issue is how are they held to account, in what context, and is it a youth-specific approach?"

The community in New Zealand is largely behind the diversionary approach, according to Dr Nessa Lynch — a youth justice expert from Wellington's Victoria University.

Dr Lynch said the diversion-focused system, which has been in place for 28 years and includes family group conferencing for more serious offending, also works for the victims.

"Because there's much more provision for participation in the actual process and the outcome, the victims are actually a lot happier than they are in the adult system," Dr Lynch said.

Courts incorporate traditional Maori or Pacific Island practices

While in New Zealand, Ms White and Mr Gooda watched a hearing at a Pasifika Court, which works within the youth court system.

According to Judge Becroft, the country now has 14 Rangatahi and two Pasifika courts, which apply local laws but are based on traditional Maori or Pacific Island practices.

"A way that's consistent with their own culture, consistent with their own language," he said.

"The law is more appropriately applied and more appropriately respected when it's done through the cultural lens of the young offender."

Since the rollout of the courts in 2008, Judge Becroft said reoffending had dropped by 10 to 15 per cent.

"But they're not primarily about reducing reoffending, they're about engendering and creating respect for the rule of law amongst a community that's been marginalised and is very suspicious if not antagonistic," he said.

The Northern Territory royal commission will be back in Darwin later this month to meet with current and former youth detention centre staff.